As intelligent terminals are widely applied, in order that UE (user equipment) simultaneously camps on a 3GPP (3rd Generation Partnership Project) network and a non-3GPP network (for example, a WLAN network), a manner in which an operating system corresponding to the UE is modified is used currently, so that services are offloaded to a 3GPP network and a non-3GPP network (for example, a WLAN network).
In the prior art, an operating system corresponding to UE is modified by means of OpenVSwitch, so that an OpenFlow function supported by the operating system implements that the terminal simultaneously camps on a 3GPP network and a non-3GPP network (for example, a WLAN network); and then, the UE successively initiates an ISMP (inter-system mobility policy) procedure and an ISRP (inter-system routing policy) procedure to an ANDSF (access network discovery and selection function) on a network side, to offload services to different networks. The ISMP procedure is used by the UE to access a non-3GPP network (for example, a WLAN network), and the ISRP procedure is used by the UE to acquire an offloading policy that is delivered by a network side, so that the UE performs service offloading according to the offloading policy.
The UE is required to first initiate the ISMP procedure before services are offloaded to a 3GPP network and a non-3GPP network (for example, a WLAN network), but the UE does not execute offloading, and the ISMP procedure is used only to join a non-3GPP network (for example, a WLAN network). Therefore, in the prior art, the ISMP procedure must be performed before the ISRP procedure is initiated, and as a result, excessive network resources are occupied.